One problem in information systems at the present time is the difficulty of attaining a high output when transferring information to or from mass memories which are part of these systems. Particularly for high-performance computers, the system element which limits its processing capacity is, as a rule, the mass memory. The problem to be solved, accordingly, is to devise a method of recording and readout, as well as a memory system with a high information capacity and allowing a high output to or from the processing units. Hence the subject of the invention is means making it possible to realize a high-output memory of such kind, having a capacity high enough to store the enormous quantity of information required for the complex calculations for which the information system is intended. The invention can advantageously be applied to all systems capable of handling very large data bases, one example being image processing systems.
In the present state of the art, only magnetic disks provide systems having a short access time at a minimum cost per bit. However, a great number of disks is required in order to attain capacities compatible with the processing power of present-day processing units. To improve the performance of the mass disk memories, the trend at the present time is to attempt to increase the density of information and the speed of readout or entry on the disks. For example, methods of what is called perpendicular recording are now in development, which increase the density of the recorded information, but these systems are still under development and threaten to be very expensive. The same is true for optical disk memories.
The solution most commonly adopted is to use a certain number of conventional magnetic disk units on which the user distributes his files in an astute manner, each file being totally on a given disk. However, when conventional disk units are used, the information recorded on one disk always presents itself in the form of words of a plurality of bits transmitted in series. This limits the information output capable of being sent between the calculating unit and the mass memory.